〔Abstract〕 Objective To explore the effect of cryoablation on apoptosis of lung adenocarcinoma cells. Methods According to the district in the tumor following cryoablation, human lung adenocarcinoma H1299 cells were divided into four groups to construct the freezing model of lung cancer in cell level: group A, untreated cells, as the control group. In group B, the necrotic solution was added to the untreated cell culture medium(the cell suspension was frozen in a liquid nitrogen tank for 5 min, and centrifuged to obtain the supernatant after rewarming at 37 ℃).Group C, sublethal cells(cells were frozen at-80 ℃ for 7 min to mimic sublethal state). In group D, necrotic solution was added into sublethal cell culture medium. Cell apoptosis was observed by flow cytometry analysis 24 h later. The expression of apoptosis related molecules Bax and Bcl-2 was detected by qRT-PCR and Western blot. Lewis lung adenocarcinoma cell line was used to establish subcutaneous transplanted tumor model of C57 BL/6 mice. The successful model mice were randomly divided into two groups: sham operation group and argon-helium cryoablation group, with 4 mice in each group. After argon-helium cryoablation for 14 days, the tumor tissues were taken. The expression of apoptosis-related molecules Bax and Bcl-2 was detected by qRT-PCR and Western blot. Results In the cell freezing model, compared with group A in the control group B,C and D groups could promote cell apoptosis(P<0.05), and group D had the highest apoptosis rate, which was significantly higher than other groups(P<0.05). Bothin vitroandin vivoexperiments showed that cryoablation could increase the expression of Bax mRNA and protein(P<0.05). Bcl-2 mRNA and protein expression decreasedin vivo(P<0.05). There was no significant change in the in cell freezing model. Conclusion Cryoablation can achieve effective ablation through cell apoptosis mechanism, which may be related to the reduction of Bcl-2/Bax.